package concurrent;

import java.util.Random;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class CountDownLatchDemo implements Runnable {

    static final CountDownLatch end = new CountDownLatch(10);
    static final CountDownLatchDemo demo = new CountDownLatchDemo();

    @Override
    public void run() {
        try {
            Thread.sleep(new Random().nextInt(10)*1000);
            System.out.println("check completed");
            end.countDown(); // 通知CountDownLatch可以减1，
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) throws InterruptedException {
        ExecutorService exec = Executors.newFixedThreadPool(10);

        for (int i=0; i<10; i++) {
            exec.submit(demo);
        }

        end.await(); // 主线程等待

        System.out.println("fire");
        exec.shutdown();
    }

}
